The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 22, 1985
Filed:
Aug. 23, 1983
Abstract
An extrusion head for producing flat profiles such as tread strips for automotive vehicles from three or more different rubber or plastics materials is disclosed. The head comprises a fixed central portion and upper and lower portions pivotally connected thereto, and is fed with the different mixtures by a plurality of screw or worm extrusion devices. Between the upper and central portion and the central and lower portions of the head, insert members are located. In the upper and/or lower surface of each insert member, flow channels for the mixtures are defined, the flow channels each being bounded upwardly or downwardly as appropriate, by a plane surface of one of the portions of the head. The insert members are axially divided and are made in one piece. The flow channels each have a longitudinal axis of symmetry and such axes lie in a common vertical plane. Such an arrangement permits the profile to be changed merely by replacing one or both insert members, permits the worms or screws to be readily removed for cleaning purposes and also ensures that the flow rates in each of the flow channels is substantially constant, thereby avoiding problems of pre-vulcanization.